This Convex-pole series-connected hybrid excitation generator has the advantages of small size and high power density, which is the main development trend of hybrid excitation generator for automobiles. The design is based on a hybrid excitation generator with built-in combined pole permanent magnet and convex pole electromagnet. The air gap magnetic density expression based on numerical analysis is derived, and a multi-objective optimization model with the rotor eccentricity and V-shaped permanent magnet clamping angle as design variables and the slot torque amplitude, no-load induced electric potential fundamental waveform amplitude and no-load induced electric potential waveform distortion rate as optimization objectives is established. The target optimization model is sampled using the Latin hypercube sample statistics, and the optimization results are screened by a combination of Pareto frontier statistics and defined parameter matching coefficients to determine the optimal rotor structure parameter combinations. Based on the optimized motor structure parameters, a prototype is fabricated and tested to verify the performance of the prototype and the correctness of the above theoretical analysis.